diff options
| -rw-r--r-- | include/trace/trace_events.h | 22 | ||||
| -rw-r--r-- | samples/trace_events/trace-events-sample.h | 27 |
2 files changed, 49 insertions, 0 deletions
diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h index acc17194c160..08810a463880 100644 --- a/include/trace/trace_events.h +++ b/include/trace/trace_events.h @@ -102,6 +102,9 @@ TRACE_MAKE_SYSTEM_STR(); #undef __string #define __string(item, src) __dynamic_array(char, item, -1) +#undef __string_len +#define __string_len(item, src, len) __dynamic_array(char, item, -1) + #undef __bitmask #define __bitmask(item, nr_bits) __dynamic_array(char, item, -1) @@ -197,6 +200,9 @@ TRACE_MAKE_SYSTEM_STR(); #undef __string #define __string(item, src) __dynamic_array(char, item, -1) +#undef __string_len +#define __string_len(item, src, len) __dynamic_array(char, item, -1) + #undef __bitmask #define __bitmask(item, nr_bits) __dynamic_array(unsigned long, item, -1) @@ -459,6 +465,9 @@ static struct trace_event_functions trace_event_type_funcs_##call = { \ #undef __string #define __string(item, src) __dynamic_array(char, item, -1) +#undef __string_len +#define __string_len(item, src, len) __dynamic_array(char, item, -1) + #undef __bitmask #define __bitmask(item, nr_bits) __dynamic_array(unsigned long, item, -1) @@ -507,6 +516,9 @@ static struct trace_event_fields trace_event_fields_##call[] = { \ #define __string(item, src) __dynamic_array(char, item, \ strlen((src) ? (const char *)(src) : "(null)") + 1) +#undef __string_len +#define __string_len(item, src, len) __dynamic_array(char, item, (len) + 1) + /* * __bitmask_size_in_bytes_raw is the number of bytes needed to hold * num_possible_cpus(). @@ -670,10 +682,20 @@ static inline notrace int trace_event_get_offsets_##call( \ #undef __string #define __string(item, src) __dynamic_array(char, item, -1) +#undef __string_len +#define __string_len(item, src, len) __dynamic_array(char, item, -1) + #undef __assign_str #define __assign_str(dst, src) \ strcpy(__get_str(dst), (src) ? (const char *)(src) : "(null)"); +#undef __assign_str_len +#define __assign_str_len(dst, src, len) \ + do { \ + memcpy(__get_str(dst), (src), (len)); \ + __get_str(dst)[len] = '\0'; \ + } while(0) + #undef __bitmask #define __bitmask(item, nr_bits) __dynamic_array(unsigned long, item, -1) diff --git a/samples/trace_events/trace-events-sample.h b/samples/trace_events/trace-events-sample.h index 13a35f7cbe66..e61471ab7d14 100644 --- a/samples/trace_events/trace-events-sample.h +++ b/samples/trace_events/trace-events-sample.h @@ -141,6 +141,33 @@ * In most cases, the __assign_str() macro will take the same * parameters as the __string() macro had to declare the string. * + * __string_len: This is a helper to a __dynamic_array, but it understands + * that the array has characters in it, and with the combined + * use of __assign_str_len(), it will allocate 'len' + 1 bytes + * in the ring buffer and add a '\0' to the string. This is + * useful if the string being saved has no terminating '\0' byte. + * It requires that the length of the string is known as it acts + * like a memcpy(). + * + * Declared with: + * + * __string_len(foo, bar, len) + * + * To assign this string, use the helper macro __assign_str_len(). + * + * __assign_str(foo, bar, len); + * + * Then len + 1 is allocated to the ring buffer, and a nul terminating + * byte is added. This is similar to: + * + * memcpy(__get_str(foo), bar, len); + * __get_str(foo)[len] = 0; + * + * The advantage of using this over __dynamic_array, is that it + * takes care of allocating the extra byte on the ring buffer + * for the '\0' terminating byte, and __get_str(foo) can be used + * in the TP_printk(). + * * __bitmask: This is another kind of __dynamic_array, but it expects * an array of longs, and the number of bits to parse. It takes * two parameters (name, nr_bits), where name is the name of the |